Series history: Oklahoma leads 3-0, but the teams haven’t played since a 79-74 overtime win at the Sports Arena in 1975.

Next up: The winner advances to Sunday’s round of 32 here against either No. 2 Georgetown or No. 15 Florida Gulf Coast.

THE COACHES

SDSU’s Steve Fisher (14th season) and Oklahoma’s Lon Kruger (second season) are close friends, as are their wives, spending time together in the offseason. They first faced each other in the Big Ten, when Fisher was at Michigan and Kruger at Illinois, and then in the Mountain West after Kruger took the UNLV job. Fisher is 14-6 all-time against Kruger, 13-5 at SDSU, and has won eight of the last nine. Fisher has the Aztecs in the NCAA Tournament for a fourth straight season. Kruger is the first coach to take five different Division I programs to the NCAA Tournament: Kansas State, Florida, Illinois, UNLV and now Oklahoma.

SDSU STARTERS

No. 2 Xavier Thames (G, 6-3, jr.): Finally returning to his old self after a lower back injury slowed him through the entire conference season. He’s scored in double figures the last four games, matching a career high, and averaged 34 minutes. He’s the guy who makes this team go.

No. 22 Chase Tapley (G, 6-3, sr.): He currently ranks second in school history in career victories with 102, but SDSU would need to reach the Elite Eight for him to catch D.J. Gay at 105. He’ll probably draw the defensive assignment on Oklahoma sharpshooter Steve Pledger.

No. 21 Jamaal Franklin (G, 6-5, jr.): Enjoy him. You may be watching his final SDSU game if, as expected, he declares for the NBA Draft. He remains the only player in the country to lead his team in points (16.7), rebounds (9.5), assists (3.2) and steals (1.52). He also is matchup nightmare for a Sooners team that starts three guards, all 6-3 or under.

No. 23 DeShawn Stephens (F, 6-8, sr.): In only his fourth year of organized basketball, Stephens is an excellent, if undersized, defensive post. He doesn’t provide much on the offensive end, averaging 5.9 points and struggling at the line (40.7 percent during conference).

SDSU BENCH

It has become less and less of a factor in recent games. Senior James Rahon has gone cold after a midseason stretch of 14, 16 and 14 points in consecutive games; he’s averaging 3.4 points in his last seven games. Freshman Skylar Spencer didn’t play less than 12 minutes for 16 straight games, and hasn’t been above 11 minutes in the last five. Freshman Winston Shepard is shooting 33 percent in his last five games. And Dwayne Polee and James Johnson rarely play.

OKLAHOMA STARTERS

No. 1 Sam Grooms (G, 6-1, sr.): Moved into the starting lineup when freshman Buddy Hield broke his foot in February. He is averaging 12.4 points and 5.5 assists in the last five games. He’s a pass-first point who doesn’t like to shoot the 3, having attempted 13 all season.

No. 2 Steven Pledger (G, 6-4, sr.): A third team all-Big 12 selection who can flat stroke it but also can be streaky. To wit: He went 2 of 17 behind the arc in the first four games of February, then a blistering 27 of 54. Now he’s 1 of his last 10. Even so, don’t expect the Aztecs to leave him.

No. 5 Je’lon Hornbeak (G, 6-3, fr.): A 4-star recruit from Texas rated the nation’s No. 24 shooting guard by Rivals.com. He has started 28 of 31 games. He, too, can shoot it but has struggled lately behind the arc (4 of his last 17).

No. 24 Romero Osby (F, 6-8, sr.): The star. Period. The first team all-Big 12 selection has carried the Sooners for most of the season, scoring at least 17 points in the last eight games (and averaging 21.5). He’s not a classic back-to-the-basket low post, preferring to catch in the mid-post and drive with his superb midrange game.

No. 22 Amath M’Baye (F, 6-9, sr.): A Wyoming transfer from France who played against Tapley, Franklin and Rahon two seasons ago. He can and will step out to launch 3s (he’s 8 of his last 19). A third team all-Big 12 selection. Stephens and Spencer likely will cover him.

OKLAHOMA BENCH

It has been depleted by injuries to Hield and senior Casey Arent (knee). Hield returned quicker than expected and played in the last three games but with limited effectiveness. Andrew Fitzgerald, a 6-8 senior forward, is the primary big off the bench, although 6-6 junior Cameron Clark can play both guard and forward. Freshman guard Isaiah Cousins started for the first half of the season but has seen his minutes diminish since.

WHEN SDSU HAS THE BALL

The hallmark of Kruger teams is pressure man-to-man defense in the halfcourt, the idea being to push your offense further from the basket than you are accustomed. He did it so well at UNLV, pressuring the point guard and denying wing entry passes, that Fisher and his staff actually tweaked their offense to use high-post entries on many sets. Kruger left for Oklahoma, but the Aztecs have kept a similar offensive philosophy and thus have built-in pressure releases. Look for the Sooners to extend their defense full-court if they get behind. But it probably comes down to something more basic: making shots. The Aztecs are shooting 43.8 percent, their worst in eight seasons.

WHEN OKLAHOMA HAS THE BALL

Expect most of the defensive attention to surround Osby, who is averaging 13.6 shots and 9.4 free throws in his last five games. In the quarterfinals of the Big 12 tournament, Iowa State successfully wore him down and Osby went scoreless over the final nine minutes as the Cyclones overcame a 12-point deficit. “We rode him the whole game,” said Grooms, the Sooners’ point guard. “After a while he got kind of tired ... We can’t require him to do everything.” It will be interesting to see if SDSU plays Osby straight up with O’Brien or Stephens, of if they double him at the risk of freeing Pledger on the perimeter.